Tap



Aug. 4, 1931. G. E. MlLL-IR TAP Filed Dec.

16, 1929 2 Sheets-Sheet g- 4, 1931- G. E. MILLER I 1,817,575

' TAP.

Filed Dec. 16, 1929 2 Sheets-Sheet 2 28 35 31 21 2 3a 3 2 s 25s I 29 I III I .1 1 b O Patented Aug.. 4, 1931 emon-Gh nt MILLERQOF E'DNA; rnunsynvnnm TAP Application filed necemheris, 1929 Serial lid-414,370.

My invention relates to taps and its princip'al object is to provide improved means for automatically collapsing the threading dies very slowly during the threading of the interior of the coupling so as to form tapered threads to fit the exterior tapered threads on pipes on which the couplings are to be screwed. This collapsing action'of the dies during the threading operation proceeds-very slowly-so thatwhen the threading" operation is completed the dies will be collapsed or moved inwardly suflicientlyto give aprodeterl'ninedtap'er of'the threads. At the con clusion of the threading operation the .dies are fully collapsed so'that the tap ma'y' be withdrawn from the coupling. Uther objects relate to details and will be better understoodaiter the tap hasbeen fully described.

Referring to the accompanying drawings;

1 is a side elevation of my improved tap with a portion brokenaway;'Fig. 2, a.

central longitudinal section of Fig. 1, parts hein'g'shown in elevation and other parts heing broken away; Fig 3, a side elevation of theme'ans by which'the bottom plate of the tap may be adjusted longitudinally thereof; and Fig. 4, across section on the ofi-set line 4-=4 on Fig. 2; I v

Onthe drawiiigs 1 designates the spindle of a tapping. machine having the flange 2 to which the flange 3 on the body 4 of the tap is secured by bolts 5.

The'body t has a number oflQngitudi-nal' holes'dopening laterally at theirloW'e'r' ends into slots 7 containing the threading dies S; At'the upperenjds 'th'e'holes 6 open outwardly into slots 9 which receive the arms 1001? the slides llw'hich are movable lengthwise in.

V the holes 6, The slides ll operate thedies' iii) in the usual inannergs'o that when the slides move upwardly the dies move inwardly when the; slides "move downwardly the dies inove out'wardly. The body l is snr'ronntled; by the collar-12 having the ihternalcirculaf 4s" groove 13 to receive the outer ends of the arms 11 so that when the oollar moved upwardly from the position shown it will causethe slides to move upwardly and when the collar is nnvd l ownwatdly the slides 3e"- 1150 move downwardly I i The collar 12 is screwed'int'othe heavy ring 14 concentric with the body l; The ringhas a pair of opp'os-iteradialslots 15 which-receive the radial blocks 16 whichav the beginning "of a threadingoperation have 1 then np erinner corners 17 engaged by up wardly and outwardl inclined wedges, 1'8 carried by the lower ends of the bars 19 seated in grooves in the body 4 andsecured therein by screws-20, only one being shown. 6 21 designates slidable pinsseated jnpon the upper face of the blocks 16"andhavingpointed' uppe ends seated'i-n' grooves 22* in the ann slijdingpieces 23; The Oiltl facesf22 ofthe slots 22 are inclined u wardly and inwardly to fit the bevel-on the upper ends of the pins 21. Springs 24 bear uponthe outer ends'ofthe'pieces 23 so asto urge the latter inwardly, thereby tending to move I the pins 21 downwardly, nd' will move-them down intothe shallow holes 21- when the blocks 16- are moved outwardly sufficiently by. the bars 28; Th -springs are heldin' "lace and adjusted by the screw plugs '25. tel erably, thesli'ding pieces 28 areheld'in a air of plates '2'6'secu'red to thenpper sideo thering ltby the-screws'26. I w

The rin'g' lt has atdiametricallyopposite places the openings arallel wi'th the axis of'the tap. Each ofthese openings reeeives the upper'end of a bar 28 having its lower end secured to thecircular plate 2 9by the" screws 30. The plate 29 ha acentral-open-- ing 30' through which the lower endfofthe threading dies'ina'y' pass, The opening 30' must be snfiiciently small to form asea't for the upper end of acoupling su-itably placed for a threading operation bythefldies B The outerifaces ofthe openings 27 are prefer= ably formedby removable 'plates' 31 The Outer faces of the bars 28: have outwardlyem tending pins 32=whic h l ride in slots 33'? in; the plates 31, the pins engaging the lower ends of the slots. whenithe bars S38 reachtheir that when theringle-is moved downwardly m the blocks 16 move outwardly, and when the ring 14 moves upwardly the blocks 16 move inwardly.

The bars 28 are adjustable in any convenient manner. I have shown the lower end thereof provided with the parallel racks 36 which fit in grooves 37 in the upper portion 38 of the bar 28. The toothed block 39 seats on the teeth on the racks 36, being clamped thereto by the screw 40 connected to the widened part 40 of the upper portion 38 of the bar 28.

Parts being as shown on Figs. 1 and 2,"

and the plate 29 resting on the upper end of the coupling 41, the spindle 1 is rotated and fed downwardly into the coupling so that the dies cut threads on the interior surface thereof. Initially the ring 14 is carried downwardly through the connection of the blocks 16 with the lower end of the wedges 18 so that as the spindle 1 and the body 4 move downwardly, the ring is moveddownwardly against the action of the springs 42, only one shown, connecting the flange 3 and the ring. As the ring moves downwardly the blocks 16 also move downwardly, the flanges 34 operating in the inclined grooves 35 to gradually move the blocks 16 outwardly. This outward movement of the blocks allows the ring which carries theslides 11 to move down at a slower speed than that taken by the body 4. This means that as the wedges 18 descend along the upper. inner corners of the blocks, the slides 11 are being gradually and slightly moved upwardly with respect to the dies 8 so as to cause the latter to be slightly retracted or collapsed. When the upper inner corners of the blocks 16 are passed by the upper ends of the wedges 18, the springs 42 immediately pull the ring upwarc lywhich through the slides 11 causes the immediate and full collapse of the dies 8. The pieces 23 are positioned inwardly by the springs so that their inner ends move into the grooves 19 in the bars 19. This movement of the spring-pressed pieces 23 causes the inclined faces 22 in the grooves 22 to wedge the pin 21 downwardly into the holes 21 in the up per faces of the blocks 16, thereby locking the blocks from outward movement, and the bars 28 and the plate 29 from moving downwardly. Thus, the plate 29 which has ascended above the coupling 41 remains in its raised positionso that the coupling may be removed without hindrancefrom the plate 29. The inner ends of the pieces 23 lie above the wedges 18 and are inclined at their lower inner corners so that when the ring 14 is moved downwardly, the pieces 23 will be wedged outwardly and thereby free the pins 21 fromthe inclined faces 22 in the grooves 22, thus, allowing the weight of the plate 29 and the bars 28 to return to their lowest I positions as shown on the drawings. I The dc scent of the bars 28 wedges the blocks 16 to their outer positions as shown in Fig. 2.

After the springs have moved the ring 14 and associated parts upwardly, the spindle can be backed off and the parts may be returned to the positions shown by hand or any well known means used for that purpose, as by the mechanism shown in my Patent No. 1,499,117, granted June 24, 1924.

The distance the blocks 16 move radially while in contact with the wedges 18 determines the amount of taper in the cutting of the threads. The groves 35 are quite long and slightly inclined so that considerable travel of the blocks downwardly in the grooves 35 moves them out radially very slowly. The plate 29 is held in proper relationto the ring 14 by means of the rods 43, only one shown, attached to the upper face of the plate and working in openings 44, only one shown, in the ring 14. Neither of the rods 43 is shown in Fig. 2 in order to prevent confusion of the lines.

In the claims I have used the term sleeve to cover the combination of the collar 12 and the ring 14 or any equivalent thereof.

I do not desire to be limited to the precise apparatus shown and described, but desire to cover all modifications thereof which come within the scope of the appending claims.

I claim: 7

1. In a tapping device, a longitudinally movable body having a free end, a sleeve slidable on the body, laterally movable threading dies carried by the free end of the body, means carried by the sleeve for moving the dies outwardly when the sleeve moves toward the free end of the body and for moving the dies inwardly when the sleeve moves in the opposite direction, a means stationary during a threading operation, a wedge movable with the body and inclined inwardly and toward the free end of the body, a sliding block carried by the sleeve and engaging the wedge and causing the feed of the sleeve by the wedge, and means connected to the stationary means for moving the block gradually outwardly as the threading operation proceeds whereby the threads on the interior of the body threaded become tapered.

2. In a tapping device, a rotary spindle, a longitudinally movable body having a base for attachment to the spindle and having a free end, a sleeve slidable on the body, laterally movable threading dies carried by the free end of the body, means carried by the sleeve for moving the dies outwardly when the sleeve moves toward the free end of the body and for moving the dies inwardly when the sleeve moves in the opposite direction, a means stationary during a threading operation, a wedge movable with the body and inclined inwardly and toward the free end of the body, a sliding block carried by the sleeve and engaging the wedge and causing the feed of the sleeve by the wedge, elastic means for tending to move the sleeve toward the base of the body and keep the block in contact with the wedge and move the sleeve quickly toward the said base when the wedge has passed the block, and means connected to the stationary means for moving the block gradually outwardly as the threading operation proceeds whereby the threads on the interior of the body threaded become tapered,

3. In a tapping device, a longitudinally movable body having a free end, asleeve slidable on the body, laterally movable threading dies carried by the free end of the body, means carried by the sleeve for moving the dies outwardly when the sleeve moves toward the free end of the body and for moving the dies inwardly when the sleeve moves f in the opposite direction, a means stationary durmg athreadmg operation, a wedge movable with the body and inclined inwardly and toward the free end of the body, a sliding block carried by the sleeve and engaging a the wedge and causing the feed of the sleeve by the Wedge, and means connected to the stationary means for moving the block gradually outwardly as the threading operation proceeds whereby the threads on the interior of the body threaded become tapered, the said connecting means comprising a flange carried by the block and slidable on a controlling surface carried by the stationary means and inclined toward the free end of the body and away from the axial center thereof.

In testimony whereof, I hereunto afiix my signature. o

GEO. E. MILLER. 

